package com.suyin.ximoon.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.http.HttpSession;


public class DisableUrlSessionFilter  implements Filter {
	 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
	        // skip non-http requests
	        if (!(request instanceof HttpServletRequest)) {
	             chain.doFilter(request, response);
	            return;
	         }
	 
	         HttpServletRequest httpRequest = (HttpServletRequest) request;
	         HttpServletResponse httpResponse = (HttpServletResponse) response;
	        // clear session if session id in URL
	        if (httpRequest.isRequestedSessionIdFromURL()) {
	             HttpSession session = httpRequest.getSession();
	            if (session != null) session.invalidate();
	         }
	        // wrap response to remove URL encoding
	         HttpServletResponseWrapper wrappedResponse = new HttpServletResponseWrapper(httpResponse) {
	             @Override
	            public String encodeRedirectUrl(String url) {
	                return url;
	             }
	 
	          
	            public String encodeRedirectURL(String url) {
	                return url;
	             }
	 
	            
	            public String encodeUrl(String url) {
	                return url;
	             }
	 
	            
	            public String encodeURL(String url) {
	                return url;
	             }
	         };
	 
	        // process next request in chain
	         chain.doFilter(request, wrappedResponse);
	     }
	 
	    /**
	      * Unused.
	     */
	    public void init(FilterConfig config) throws ServletException {
	     }
	 
	    /**
	      * Unused.
	     */
	    public void destroy() {
	     }

}
